Removable fire-box.



No. 777,598. PATENTED DEC. 13, 1904.

F. BURGER & H. M. WILLIAMS.

REMOVABLE FIRE BOX.

APPLICATION FILED MAILZG, 1902.

2 SHEETS-SHEET 1 H0 MODEL.

Albums:

I Ulloznup No. 777,593. PATENTED DEC. 13, 1904;. F. BURGER & H. M. WILLIAMS REMOVABLE FIRE BOX.

AIPL'IGATION FILED MAR. 26, 1902 N0 MODEL. 2SHEETS-SHEBT 2 M ginuauroz GHQ: new:

UNITED STATES Patented December 13, 1904.

PATENT OFFICE.

FRANZ BURGER AND HENRY M. WILLIAMS, OF FORT WAYNE, INDIANA;

SAID BURGER ASSIGNOR OF ONE-HALF OF HIS RIGITII TO SAID VVIL- LIAMS.

REMOVABLE FIRE-BOX.

SPECIFICATION forming part of Letters Patent No. 777,593, dated December 13, 1904.

Application filed March 26, 1902.

To all whom it may concern:

Be it known that we, FRANZ BURGER and HENRY M. WILLIAMS, both citizens of the United States, residing at Fort Wayne, in the county of Allen and State of Indiana, have invented certain new and useful Improvements in Removable Fire Boxes with Secondary Combustion-Chambers, of which the following is a specification.

This invention relates to steam-boilers, its principal objects being to provide the boiler with a secondary combustion-chamber outside of the fire-box, but within the boiler, and also to so construct the fire-box and support it within the combustion chamber that it can readily be removed whenever desired.

The invention will be fully described hereinafter, reference being had to the accompanying drawings, in which- Figure 1 is a vertical longitudinal section of a portion of a boiler embodying our invention. Fig. 2 is a vertical transverse section. Fig. 3 is a horizontal section.

The outer shell 1 of the boiler is provided with the usual steam-dome 2. l/Vithin the shell 1 another shell 3 is supported eccentrically to the outer shell and is provided, with a head 4: at its inner end, which forms the tubesheet for supporting one end of the fire-tubes 5. At its outer end the shell 3 is united. to the shell 1 by a head 6, which closes this end of the steam and water space of the boiler.

"Within the shell 3, and preferably concentric therewith, the fire-box 7 is supported to leave an annular space 9 between them, and the fire-box is also shorter than the shell 3 to leave a space between the inner ends of the fire-box and shell 3, and the said annular and end spaces form the secondary combustion chamber. The fire-box consists of an outer shell 8 and an inner shell 10, the inner shell 10 being sufliciently small to leave a waterspace between the shells. The inner ends of the shells 8 and 10 are respectively provided with heads 11 and 12, spaced apart to leave a water-space, and each head is provided with a narrow elongated opening 13. A flattened. tube 14 is secured between the heads 11 and 12 to bridge the space between the shells and Serial No. 100,052. (No model.)

form, with the apertures 13, a continuous passage through the inner end of the fire-box. At their outer ends the shells 8 and 10 are united by a ring 15, and the outer shell 8 projects beyond the ring 15. On this projecting portion of the shell 8 a ring-shaped angle-iron 16 is secured in any suitable manner, and the vertical flange of this angle-iron is bolted to the head 6 by bolts 17. The outer end of the lire-box is closed by a head 18, which is socured to the ring by screws 19, and the head is provided with a stoke-hole 20 and ashhole 21.

The lire-box is provided with grate-bars 22, of any approved pattern and preferablysupported to be vibrated for the purpose of feeding the fuel progressively from the front to the rear of the furnace. Bars of this character are well known and need not be particularly described nor the mechanism for vibrating them. The idea is to move the fuel gradually from the front to the rear of the lire-box and through the narrow elongated passage onto an auxiliary grate 23, which will preferably be hinged at the edge adjacent to the firebox in order that it may be dumped when necessary. A bridge-wall 24: will prevent any further progress of the fuel. The grate-bars 22 are preferably pivoted to angle-bars 25, supported by the shell 10, and these anglebars also serve to support the fire-walls 26, which extend the entire length of the lire-box, and the burning fuel will be confined between these walls. Spaces 27 are left between the walls 26 and the sides of the shell 10, and a series of downwardly-inelined tubes 28 establish communication between the spaces 27 and the annular space 9, and the products of combustion will thus pass out of the fire-box into the secondary combustion-0ha1nber.

It is necessary to establish communication between the water-s iace between the shells8 and 10 and the main water-space of the boiler, and while this may be accomplished in various ways we prefer to provide a short tube 29 at the bottom of the boiler near the front, provided with flanges 30 and 31, the flange 30 being preferably riveted to the shell 8 and the flange 31 bolted to the shell 3 by threaded bolts and nuts 32. A manhole 33 in the bottom of the shell 1 will permit access to the nuts and bolts 32. The shells 8 and 3 are cut out within the bounds of the tube 29. A similar connection (indicated by 3a) is provided. to establish communication at the upper part of the main water-space. To form an additional support for the inner end of the shell 3, suspension-links 35 may connect it to the shell 1. Similar links 36 may connect the inner end of the fire-box to the shell 3.

A manhole 37 is provided in the bottom of the boiler, through which entrance may be had to the interior of the combustion-chamber either for cleaning or repairing the fines or for connecting or disconnecting the links 36. Ashes and cinders dumped from the grate 23 will also be removed through this manhole. A hinged door 38 serves to close the manhole, which may be locked by any suitable means, such as indicated by 38.

Preferably a forced-blast apparatus, such as described in our Patent No. 660, 557, granted October 30, 1900, will be employed to deliver air below the grate-bars 22, and a special pipe may be provided to deliver air below the grate 23. \Ve have not deemed it necessary to illustrate these devices and only refer to them in order to point out farther on some of the advantages that may be derived from our invention.

The fuel will be fed through the opening 20 in the front plate 18, and the latter will preferably be lined with fire-brick. The fuel will be moved progressively from the front to the rear of the furnace and be gradually consumed, and such as is not consumed within the fire-box will pass through the narrow elongated passage at the end of the fire-box on to the grate 23, and by supplying additional air to this grate, as suggested, a fire can be maintained on this grate. Vhen the fuel is burning in the fire-box, the hot gases will fill up the furnace-space and pass thence through the tubes 28 into the secondary combustionchamber. The fire-walls 26 insure that the gases must first ascend and then descend before escaping through the tubes 28, and this causes the upper part of shell 10 to become highly heated, which heat will beimparted to the water in the space between shells 8 and 10. After passing through the tubes 28 the hot gases will fill the secondary combustion-chamber and impart heat to the shells 8 and 3, which in turn will impart it to the water, and from the secondary combustion-chamber the hot gases will pass through the tubes, and if only a slight induced draft be employed, as can be the case when a forced blast is delivered below the grate-bars, the velocity of the gases through the tubes will not be great and much more heat will be imparted to the tubes than is possible with a strong induced draft. The

fire-walls 26 being within the furnace will become red-hot, which will aid greatly in the prevention of smoke, as the gases must come in contact with these walls in their passage to the tubes 28. Should any unconsumed carbon pass through the tubes 28, it will be brought into contact with the fire on the grate 23 and be there consumed, and a practically smokeless gas will pass into the fire-tubes 5. The production of smoke is largely the result of a low heat in the furnace, and when carbon has once left the furnaceno amount of air will bring it to incandescence again, and it is only by bringing it into contact with an incandescent body that the carbon can be consumed. This incandescent body we provide by having a fire on the grate 23 in the secondary combustion-chamber.

It will be seen that by the construction illustrated and described we gain an increased heating'surface and the products of combustion are utilized to a much greater extent than has been generally possible heretofore and that the carbon is almost, if not entirely, consumed, with the resultthat little, if any, smoke will escape from the furnace.

In case it may be necessary the fire-box can be bodily removed from the boiler. The bolts 32 can easily be removed through the manhole 33, and entrance may be had to the secondary combustion-chamber through the manhole 37 for the purpose of disconnecting the links. 7 The bolts of the connection 3 1 can also be removed by getting into the water-space of the boiler below the dome, and then by removing the bolts 17 the fire-box can be pulled out bodily, and evidently this will greatly facilitate the making of repairs.

\Vithout limiting ourselves to the precise details of construction illustrated and described, we claim- 1. In a fire-tube steam-boiler, the combination of a shell supported within the waterspace of the boiler, and having a head at its inner end in which the fire-tubes are support ed, a fire-box supported within the said shell to leave a space between them to form a secondary combustion-chamber, and connections between the fire-box and said chamber, substantially as set forth.

2. A fire-tube boiler provided with a secondary combustion-chamber inclosing the firebox and communicating therewith and with the fire-tubes of the boiler, and means for supporting combustible fuel in the secondary combustion-chamber, substantially as set forth.

3. In a boiler, the combination of a shell supported within the water-space of the boiler, a fire-box supported within the shell to leave a space between them to form a secondary combustion-chamber, said fire-box having a head at its inner end provided with a narrow elongated opening, through which fuel may pass, a grate within the fire-box, and a grate in said combustion-chamber to receive fuel passing through the said opening, substantially as set forth.

wases i. In a boiler, the combination of a shell supported within the water-space of the boiler, a water-jacketed fire-box supported within the said shell to leave a space between them to form a secondary com bustion-chainber, a grate in said fire-box, vertical firewalls at each side of the grate spaced from the sides of the lirebox, and tubes extending through the water jacket and leading from the spaces between the lire-walls and the sides of the fire-box into the secondary combustion-chamber, substantially as set forth.

5. In a tire-tube boiler, the combination with a shell supported within the water-space of the boiler and having a head at its inner end supporting the fire-tubes, a water-jacketed fire box supported within the shell to leave a space between them to form a secondary combustion-chamber, tubes extending through the water-jacket to afford communication between the fire-box and said chamber, connections between the water-jacket and the water-space of the boiler, and a grate in the secondary coinbustion-chamber to supportfuel, substantially as set forth.

6. In a lire-tube boiler, the combination of a lire-box having a head at its inner end provided with a narrow elongated opening, a coinbustion-chamber surrounding the lirc-box and communicating therewith and with the liretubes, a hinged grate in the combustion-chainber adjacent to said elongated opening, means to feed burning fuel through the opening onto said grate, a bridge-wall to limit the movement of fuel on the grate, and a removable door closing an opening to the combustioncliamber below the grate, substantially as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

FRANZ BURGER. HENRY M. WILLIAMS.

Witnesses:

GEO. K. TORRENCE, C. B. l VA'rnns. 

